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diff --git a/portaudio/doc/src/tutorial/querying_devices.dox b/portaudio/doc/src/tutorial/querying_devices.dox deleted file mode 100644 index 1eac41a..0000000 --- a/portaudio/doc/src/tutorial/querying_devices.dox +++ /dev/null @@ -1,111 +0,0 @@ -/** @page querying_devices Enumerating and Querying PortAudio Devices -@ingroup tutorial - -@section tut_query1 Querying Devices - -It is often fine to use the default device as we did previously in this tutorial, but there are times when you'll want to explicitly choose the device from a list of available devices on the system. To see a working example of this, check out pa_devs.c in the tests/ directory of the PortAudio source code. To do so, you'll need to first initialize PortAudio and Query for the number of Devices: - -@code - int numDevices; - - numDevices = Pa_GetDeviceCount(); - if( numDevices < 0 ) - { - printf( "ERROR: Pa_CountDevices returned 0x%x\n", numDevices ); - err = numDevices; - goto error; - } -@endcode - - -If you want to get information about each device, simply loop through as follows: - -@code - const PaDeviceInfo *deviceInfo; - - for( i=0; i<numDevices; i++ ) - { - deviceInfo = Pa_GetDeviceInfo( i ); - ... - } -@endcode - -The Pa_DeviceInfo structure contains a wealth of information such as the name of the devices, the default latency associated with the devices and more. The structure has the following fields: - -@code -int structVersion -const char * name -PaHostApiIndex hostApi -int maxInputChannels -int maxOutputChannels -PaTime defaultLowInputLatency -PaTime defaultLowOutputLatency -PaTime defaultHighInputLatency -PaTime defaultHighOutputLatency -double defaultSampleRate -@endcode - -You may notice that you can't determine, from this information alone, whether or not a particular sample rate is supported. This is because some devices support ranges of sample rates, others support, a list of sample rates, and still others support some sample rates and number of channels combinations but not others. To get around this, PortAudio offers a function for testing a particular device with a given format: - -@code - const PaStreamParameters *inputParameters; - const PaStreamParameters *outputParameters; - double desiredSampleRate; - ... - PaError err; - - err = Pa_IsFormatSupported( inputParameters, outputParameters, desiredSampleRate ); - if( err == paFormatIsSupported ) - { - printf( "Hooray!\n"); - } - else - { - printf("Too Bad.\n"); - } -@endcode - -Filling in the inputParameters and outputParameters fields is shown in a moment. - -Once you've found a configuration you like, or one you'd like to go ahead and try, you can open the stream by filling in the PaStreamParameters structures, and calling Pa_OpenStream: - -@code - double srate = ... ; - PaStream *stream; - unsigned long framesPerBuffer = ... ; //could be paFramesPerBufferUnspecified, in which case PortAudio will do its best to manage it for you, but, on some platforms, the framesPerBuffer will change in each call to the callback - PaStreamParameters outputParameters; - PaStreamParameters inputParameters; - - bzero( &inputParameters, sizeof( inputParameters ) ); //not necessary if you are filling in all the fields - inputParameters.channelCount = inChan; - inputParameters.device = inDevNum; - inputParameters.hostApiSpecificStreamInfo = NULL; - inputParameters.sampleFormat = paFloat32; - inputParameters.suggestedLatency = Pa_GetDeviceInfo(inDevNum)->defaultLowInputLatency ; - inputParameters.hostApiSpecificStreamInfo = NULL; //See you specific host's API docs for info on using this field - - - bzero( &outputParameters, sizeof( outputParameters ) ); //not necessary if you are filling in all the fields - outputParameters.channelCount = outChan; - outputParameters.device = outDevNum; - outputParameters.hostApiSpecificStreamInfo = NULL; - outputParameters.sampleFormat = paFloat32; - outputParameters.suggestedLatency = Pa_GetDeviceInfo(outDevNum)->defaultLowOutputLatency ; - outputParameters.hostApiSpecificStreamInfo = NULL; //See you specific host's API docs for info on using this field - - err = Pa_OpenStream( - &stream, - &inputParameters, - &outputParameters, - srate, - framesPerBuffer, - paNoFlag, //flags that can be used to define dither, clip settings and more - portAudioCallback, //your callback function - (void *)this ); //data to be passed to callback. In C++, it is frequently (void *)this - //don't forget to check errors! -@endcode - - -Previous: \ref utility_functions | Next: \ref blocking_read_write - -*/
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